1. Field of the Invention
The present invention relates to the field of chemistry, and in particular refers to a method for activation and regeneration of filter materials that are used for filtering fluids for human and animal consumption, as well as to the regenerated and activated materials which are obtained with the mentioned method.
2. Description of Related Art
Obtaining clean, drinkable and pure water coming from different sources, it is a never-ending task. It is common to find water contaminated by different causes and the lack of safety in the quality of water is a danger which the majority of the countries of the world do not escape from. Pollution levels lead to the constant search for systems for its disposal, and so, the use of filters is essential, these filters may be of different materials, depending on the pollutant that you want to eliminate. However the use of filters at the same time, contains another drawback, with them the contaminants are eliminated, but the contaminants are retained in the filters, and when the maximum limit of retention is reached (culmination of its useful life), it is necessary to replace it with another one, and this is where the new problem is generated, the environmental pollution due to the need for replacement of filters
There is a wide variety of materials which are used in filters, where inorganic surfaces play an important role, both for contaminants that eliminated, as for the processes of regeneration. The aluminosilicates have different proportions of aluminium and silicon, which originates different structures, and also varied properties. Zeolite has been one of the materials most used for this purpose, due to its low cost and easy availability.
Other microporous hydrophobic materials have also been described (document WO 2007056717) for the production of filter devices. Methods have also been reported and compositions for removal of arsenic contamination of the water, where this method is based on the use of pumice covered with rusted metal (application for patent No. 2007017871 US).
Additionally, the patent application No. AU 2011340169, describes an organic-inorganic composite material based on metal, carbon and nitrogen oxide and other functional elements/groups for the removal of anionic contaminants such as arsenic, fluoride, etc. from water, and methods for making the same. The organic-inorganic compound may be produced from at least one biogenic material, such as chitin, Chitosan, bio-membrane and a metal salt such as iron, aluminium, etc. The organic-inorganic compound shows a high capacity of absorption of arsenic and fluoride under different conditions. In addition, this document describes a surprising regeneration of 98%-99%, using a new protocol for regeneration.
A wastewater purification method is described in patent application No. US 2013292336, is based on the use of catalytic oxidation for the removal of soluble metals. Catalytic oxidation can produce filtered water saturated with oxygen and high pH, resulting in a greater precipitation of soluble metals, when softening agents, such as sodium carbonate, are added in a stage of further processing.
In addition to the materials used for the removal of contaminants from liquids, several methods have been described, for the regeneration of these filter materials, for example, document WO2009000429, refers to a method for the regeneration of zeolite used for the treatment of contaminated water, said regeneration method is based on the use of heat energy in the presence of an air flow. The document WO2008022562 also describes a method for regeneration of adsorbent and filter material which is based on the use of thermal energy.
On the other hand, the patent application No. US 2009261042 discloses a filter made of an adsorbent material and regeneration treatment thereof through the use of nanoparticles.
Most of the methods for the regeneration of filter materials which are described in the literature on the subject, agree on the use of the heat energy as a way to remove impurities adsorbed to them (WO 2008022562, DE4443628, U.S. Pat. No. 6,676,839) for both zeolite and activated carbon.
Other methods (document WO 9102699) report the use of microwave radiation to remove or modify unwanted materials from the surface of a particulate substrate. This method is particularly useful for recyclable substrates for subsequent or later use. In this patent the treatment of alumina with microwave radiation for the removal of organic chemical compounds, is exemplified.
On the other hand, U.S. Pat. No. 5,262,024 reports a desorption process of ionic species associated to a matrix through the application of an energy wave. This document mentions that the desorption energy, can be microwave power, ultrasonic and sonic energy, as well as an electromagnetic potential, and that the electrolytes can enhance desorption. However, the realization examples of this document however, teach that this method works for soil contaminated with uranium and that electrolytes did not represent an improvement in the shown desorption process.